Nixon says the factors that led to the 47-year-old's conviction for the kidnapping, rape and murder of 11-year-old Elissa Self in 1991 have not changed.

Link's attorney has two court appeals pending, one before a federal judge, the other before the Missouri Supreme Court. Both question the legality of Missouri's lethal injection protocol.

Elissa disappeared while walking to her school bus stop in south St. Louis on Jan. 11, 1991. Her body was found four days later along the banks of the St. Francis River, some 135 miles south of St. Louis.